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49 <div class="headertitle">
50 <h1>arm_lms_q31.c</h1> </div>
52 <div class="contents">
53 <a href="arm__lms__q31_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* ---------------------------------------------------------------------- </span>
54 <a name="l00002"></a>00002 <span class="comment">* Copyright (C) 2010 ARM Limited. All rights reserved. </span>
55 <a name="l00003"></a>00003 <span class="comment">* </span>
56 <a name="l00004"></a>00004 <span class="comment">* $Date: 15. July 2011 </span>
57 <a name="l00005"></a>00005 <span class="comment">* $Revision: V1.0.10 </span>
58 <a name="l00006"></a>00006 <span class="comment">* </span>
59 <a name="l00007"></a>00007 <span class="comment">* Project: CMSIS DSP Library </span>
60 <a name="l00008"></a>00008 <span class="comment">* Title: arm_lms_q31.c </span>
61 <a name="l00009"></a>00009 <span class="comment">* </span>
62 <a name="l00010"></a>00010 <span class="comment">* Description: Processing function for the Q31 LMS filter. </span>
63 <a name="l00011"></a>00011 <span class="comment">* </span>
64 <a name="l00012"></a>00012 <span class="comment">* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0</span>
65 <a name="l00013"></a>00013 <span class="comment">* </span>
66 <a name="l00014"></a>00014 <span class="comment">* Version 1.0.10 2011/7/15 </span>
67 <a name="l00015"></a>00015 <span class="comment">* Big Endian support added and Merged M0 and M3/M4 Source code. </span>
68 <a name="l00016"></a>00016 <span class="comment">* </span>
69 <a name="l00017"></a>00017 <span class="comment">* Version 1.0.3 2010/11/29 </span>
70 <a name="l00018"></a>00018 <span class="comment">* Re-organized the CMSIS folders and updated documentation. </span>
71 <a name="l00019"></a>00019 <span class="comment">* </span>
72 <a name="l00020"></a>00020 <span class="comment">* Version 1.0.2 2010/11/11 </span>
73 <a name="l00021"></a>00021 <span class="comment">* Documentation updated. </span>
74 <a name="l00022"></a>00022 <span class="comment">* </span>
75 <a name="l00023"></a>00023 <span class="comment">* Version 1.0.1 2010/10/05 </span>
76 <a name="l00024"></a>00024 <span class="comment">* Production release and review comments incorporated. </span>
77 <a name="l00025"></a>00025 <span class="comment">* </span>
78 <a name="l00026"></a>00026 <span class="comment">* Version 1.0.0 2010/09/20 </span>
79 <a name="l00027"></a>00027 <span class="comment">* Production release and review comments incorporated </span>
80 <a name="l00028"></a>00028 <span class="comment">* </span>
81 <a name="l00029"></a>00029 <span class="comment">* Version 0.0.7 2010/06/10 </span>
82 <a name="l00030"></a>00030 <span class="comment">* Misra-C changes done </span>
83 <a name="l00031"></a>00031 <span class="comment">* -------------------------------------------------------------------- */</span>
84 <a name="l00032"></a>00032
85 <a name="l00033"></a>00033 <span class="preprocessor">#include "<a class="code" href="arm__math_8h.html">arm_math.h</a>"</span>
86 <a name="l00069"></a><a class="code" href="group___l_m_s.html#ga6a0abfe6041253a6f91c63b383a64257">00069</a> <span class="keywordtype">void</span> <a class="code" href="group___l_m_s.html#ga6a0abfe6041253a6f91c63b383a64257" title="Processing function for Q31 LMS filter.">arm_lms_q31</a>(
87 <a name="l00070"></a>00070 <span class="keyword">const</span> <a class="code" href="structarm__lms__instance__q31.html" title="Instance structure for the Q31 LMS filter.">arm_lms_instance_q31</a> * S,
88 <a name="l00071"></a>00071 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pSrc,
89 <a name="l00072"></a>00072 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pRef,
90 <a name="l00073"></a>00073 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pOut,
91 <a name="l00074"></a>00074 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pErr,
92 <a name="l00075"></a>00075 uint32_t <a class="code" href="arm__fir__example__f32_8c.html#ab6558f40a619c2502fbc24c880fd4fb0">blockSize</a>)
93 <a name="l00076"></a>00076 {
94 <a name="l00077"></a>00077 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pState = S-><a class="code" href="structarm__lms__instance__q31.html#a206d47b49de6f357f933ebe61520753c">pState</a>; <span class="comment">/* State pointer */</span>
95 <a name="l00078"></a>00078 uint32_t numTaps = S-><a class="code" href="structarm__lms__instance__q31.html#ac0d84f7d054555931ef8a62511fbcb8a">numTaps</a>; <span class="comment">/* Number of filter coefficients in the filter */</span>
96 <a name="l00079"></a>00079 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pCoeffs = S-><a class="code" href="structarm__lms__instance__q31.html#a4afe56e991a5416adfd462aa88bda500">pCoeffs</a>; <span class="comment">/* Coefficient pointer */</span>
97 <a name="l00080"></a>00080 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pStateCurnt; <span class="comment">/* Points to the current sample of the state */</span>
98 <a name="l00081"></a>00081 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> mu = S-><a class="code" href="structarm__lms__instance__q31.html#acb6ca9996b3c5f740d5d6c8e9f4f1d46">mu</a>; <span class="comment">/* Adaptive factor */</span>
99 <a name="l00082"></a>00082 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *px; <span class="comment">/* Temporary pointer for state */</span>
100 <a name="l00083"></a>00083 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pb; <span class="comment">/* Temporary pointer for coefficient buffer */</span>
101 <a name="l00084"></a>00084 uint32_t tapCnt, blkCnt; <span class="comment">/* Loop counters */</span>
102 <a name="l00085"></a>00085 <a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a> acc; <span class="comment">/* Accumulator */</span>
103 <a name="l00086"></a>00086 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> e = 0; <span class="comment">/* error of data sample */</span>
104 <a name="l00087"></a>00087 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> alpha; <span class="comment">/* Intermediate constant for taps update */</span>
105 <a name="l00088"></a>00088 uint8_t shift = (uint8_t) (32u - (S-><a class="code" href="structarm__lms__instance__q31.html#a4705a8f0011bb9166e09bf5bd51e595e">postShift</a> + 1u)); <span class="comment">/* Shift to be applied to the output */</span>
106 <a name="l00089"></a>00089 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> coef; <span class="comment">/* Temporary variable for coef */</span>
107 <a name="l00090"></a>00090
108 <a name="l00091"></a>00091 <span class="comment">/* S->pState points to buffer which contains previous frame (numTaps - 1) samples */</span>
109 <a name="l00092"></a>00092 <span class="comment">/* pStateCurnt points to the location where the new input data should be written */</span>
110 <a name="l00093"></a>00093 pStateCurnt = &(S-><a class="code" href="structarm__lms__instance__q31.html#a206d47b49de6f357f933ebe61520753c">pState</a>[(numTaps - 1u)]);
111 <a name="l00094"></a>00094
112 <a name="l00095"></a>00095 <span class="comment">/* Initializing blkCnt with blockSize */</span>
113 <a name="l00096"></a>00096 blkCnt = <a class="code" href="arm__fir__example__f32_8c.html#ab6558f40a619c2502fbc24c880fd4fb0">blockSize</a>;
114 <a name="l00097"></a>00097
115 <a name="l00098"></a>00098
116 <a name="l00099"></a>00099 <span class="preprocessor">#ifndef ARM_MATH_CM0</span>
117 <a name="l00100"></a>00100 <span class="preprocessor"></span>
118 <a name="l00101"></a>00101 <span class="comment">/* Run the below code for Cortex-M4 and Cortex-M3 */</span>
119 <a name="l00102"></a>00102
120 <a name="l00103"></a>00103 <span class="keywordflow">while</span>(blkCnt > 0u)
121 <a name="l00104"></a>00104 {
122 <a name="l00105"></a>00105 <span class="comment">/* Copy the new input sample into the state buffer */</span>
123 <a name="l00106"></a>00106 *pStateCurnt++ = *pSrc++;
124 <a name="l00107"></a>00107
125 <a name="l00108"></a>00108 <span class="comment">/* Initialize state pointer */</span>
126 <a name="l00109"></a>00109 px = pState;
127 <a name="l00110"></a>00110
128 <a name="l00111"></a>00111 <span class="comment">/* Initialize coefficient pointer */</span>
129 <a name="l00112"></a>00112 pb = pCoeffs;
130 <a name="l00113"></a>00113
131 <a name="l00114"></a>00114 <span class="comment">/* Set the accumulator to zero */</span>
132 <a name="l00115"></a>00115 acc = 0;
133 <a name="l00116"></a>00116
134 <a name="l00117"></a>00117 <span class="comment">/* Loop unrolling. Process 4 taps at a time. */</span>
135 <a name="l00118"></a>00118 tapCnt = numTaps >> 2;
136 <a name="l00119"></a>00119
137 <a name="l00120"></a>00120 <span class="keywordflow">while</span>(tapCnt > 0u)
138 <a name="l00121"></a>00121 {
139 <a name="l00122"></a>00122 <span class="comment">/* Perform the multiply-accumulate */</span>
140 <a name="l00123"></a>00123 <span class="comment">/* acc += b[N] * x[n-N] */</span>
141 <a name="l00124"></a>00124 acc += ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) (*px++)) * (*pb++);
142 <a name="l00125"></a>00125
143 <a name="l00126"></a>00126 <span class="comment">/* acc += b[N-1] * x[n-N-1] */</span>
144 <a name="l00127"></a>00127 acc += ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) (*px++)) * (*pb++);
145 <a name="l00128"></a>00128
146 <a name="l00129"></a>00129 <span class="comment">/* acc += b[N-2] * x[n-N-2] */</span>
147 <a name="l00130"></a>00130 acc += ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) (*px++)) * (*pb++);
148 <a name="l00131"></a>00131
149 <a name="l00132"></a>00132 <span class="comment">/* acc += b[N-3] * x[n-N-3] */</span>
150 <a name="l00133"></a>00133 acc += ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) (*px++)) * (*pb++);
151 <a name="l00134"></a>00134
152 <a name="l00135"></a>00135 <span class="comment">/* Decrement the loop counter */</span>
153 <a name="l00136"></a>00136 tapCnt--;
154 <a name="l00137"></a>00137 }
155 <a name="l00138"></a>00138
156 <a name="l00139"></a>00139 <span class="comment">/* If the filter length is not a multiple of 4, compute the remaining filter taps */</span>
157 <a name="l00140"></a>00140 tapCnt = numTaps % 0x4u;
158 <a name="l00141"></a>00141
159 <a name="l00142"></a>00142 <span class="keywordflow">while</span>(tapCnt > 0u)
160 <a name="l00143"></a>00143 {
161 <a name="l00144"></a>00144 <span class="comment">/* Perform the multiply-accumulate */</span>
162 <a name="l00145"></a>00145 acc += ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) (*px++)) * (*pb++);
163 <a name="l00146"></a>00146
164 <a name="l00147"></a>00147 <span class="comment">/* Decrement the loop counter */</span>
165 <a name="l00148"></a>00148 tapCnt--;
166 <a name="l00149"></a>00149 }
167 <a name="l00150"></a>00150
168 <a name="l00151"></a>00151 <span class="comment">/* Converting the result to 1.31 format */</span>
169 <a name="l00152"></a>00152 <span class="comment">/* Store the result from accumulator into the destination buffer. */</span>
170 <a name="l00153"></a>00153 acc = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (acc >> shift);
171 <a name="l00154"></a>00154
172 <a name="l00155"></a>00155 *pOut++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) acc;
173 <a name="l00156"></a>00156
174 <a name="l00157"></a>00157 <span class="comment">/* Compute and store error */</span>
175 <a name="l00158"></a>00158 e = *pRef++ - (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) acc;
176 <a name="l00159"></a>00159
177 <a name="l00160"></a>00160 *pErr++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) e;
178 <a name="l00161"></a>00161
179 <a name="l00162"></a>00162 <span class="comment">/* Compute alpha i.e. intermediate constant for taps update */</span>
180 <a name="l00163"></a>00163 alpha = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) e * mu) >> 31);
181 <a name="l00164"></a>00164
182 <a name="l00165"></a>00165 <span class="comment">/* Initialize state pointer */</span>
183 <a name="l00166"></a>00166 <span class="comment">/* Advance state pointer by 1 for the next sample */</span>
184 <a name="l00167"></a>00167 px = pState++;
185 <a name="l00168"></a>00168
186 <a name="l00169"></a>00169 <span class="comment">/* Initialize coefficient pointer */</span>
187 <a name="l00170"></a>00170 pb = pCoeffs;
188 <a name="l00171"></a>00171
189 <a name="l00172"></a>00172 <span class="comment">/* Loop unrolling. Process 4 taps at a time. */</span>
190 <a name="l00173"></a>00173 tapCnt = numTaps >> 2;
191 <a name="l00174"></a>00174
192 <a name="l00175"></a>00175 <span class="comment">/* Update filter coefficients */</span>
193 <a name="l00176"></a>00176 <span class="keywordflow">while</span>(tapCnt > 0u)
194 <a name="l00177"></a>00177 {
195 <a name="l00178"></a>00178 <span class="comment">/* coef is in 2.30 format */</span>
196 <a name="l00179"></a>00179 coef = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) alpha * (*px++)) >> (32));
197 <a name="l00180"></a>00180 <span class="comment">/* get coef in 1.31 format by left shifting */</span>
198 <a name="l00181"></a>00181 *pb = <a class="code" href="arm__math_8h.html#ad7373e53d3c2e1adfeafc8c2e9720b5c" title="Clips Q63 to Q31 values.">clip_q63_to_q31</a>((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * pb + (coef << 1u));
199 <a name="l00182"></a>00182 <span class="comment">/* update coefficient buffer to next coefficient */</span>
200 <a name="l00183"></a>00183 pb++;
201 <a name="l00184"></a>00184
202 <a name="l00185"></a>00185 coef = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) alpha * (*px++)) >> (32));
203 <a name="l00186"></a>00186 *pb = <a class="code" href="arm__math_8h.html#ad7373e53d3c2e1adfeafc8c2e9720b5c" title="Clips Q63 to Q31 values.">clip_q63_to_q31</a>((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * pb + (coef << 1u));
204 <a name="l00187"></a>00187 pb++;
205 <a name="l00188"></a>00188
206 <a name="l00189"></a>00189 coef = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) alpha * (*px++)) >> (32));
207 <a name="l00190"></a>00190 *pb = <a class="code" href="arm__math_8h.html#ad7373e53d3c2e1adfeafc8c2e9720b5c" title="Clips Q63 to Q31 values.">clip_q63_to_q31</a>((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * pb + (coef << 1u));
208 <a name="l00191"></a>00191 pb++;
209 <a name="l00192"></a>00192
210 <a name="l00193"></a>00193 coef = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) alpha * (*px++)) >> (32));
211 <a name="l00194"></a>00194 *pb = <a class="code" href="arm__math_8h.html#ad7373e53d3c2e1adfeafc8c2e9720b5c" title="Clips Q63 to Q31 values.">clip_q63_to_q31</a>((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * pb + (coef << 1u));
212 <a name="l00195"></a>00195 pb++;
213 <a name="l00196"></a>00196
214 <a name="l00197"></a>00197 <span class="comment">/* Decrement the loop counter */</span>
215 <a name="l00198"></a>00198 tapCnt--;
216 <a name="l00199"></a>00199 }
217 <a name="l00200"></a>00200
218 <a name="l00201"></a>00201 <span class="comment">/* If the filter length is not a multiple of 4, compute the remaining filter taps */</span>
219 <a name="l00202"></a>00202 tapCnt = numTaps % 0x4u;
220 <a name="l00203"></a>00203
221 <a name="l00204"></a>00204 <span class="keywordflow">while</span>(tapCnt > 0u)
222 <a name="l00205"></a>00205 {
223 <a name="l00206"></a>00206 <span class="comment">/* Perform the multiply-accumulate */</span>
224 <a name="l00207"></a>00207 coef = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) alpha * (*px++)) >> (32));
225 <a name="l00208"></a>00208 *pb = <a class="code" href="arm__math_8h.html#ad7373e53d3c2e1adfeafc8c2e9720b5c" title="Clips Q63 to Q31 values.">clip_q63_to_q31</a>((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * pb + (coef << 1u));
226 <a name="l00209"></a>00209 pb++;
227 <a name="l00210"></a>00210
228 <a name="l00211"></a>00211 <span class="comment">/* Decrement the loop counter */</span>
229 <a name="l00212"></a>00212 tapCnt--;
230 <a name="l00213"></a>00213 }
231 <a name="l00214"></a>00214
232 <a name="l00215"></a>00215 <span class="comment">/* Decrement the loop counter */</span>
233 <a name="l00216"></a>00216 blkCnt--;
234 <a name="l00217"></a>00217 }
235 <a name="l00218"></a>00218
236 <a name="l00219"></a>00219 <span class="comment">/* Processing is complete. Now copy the last numTaps - 1 samples to the </span>
237 <a name="l00220"></a>00220 <span class="comment"> satrt of the state buffer. This prepares the state buffer for the </span>
238 <a name="l00221"></a>00221 <span class="comment"> next function call. */</span>
239 <a name="l00222"></a>00222
240 <a name="l00223"></a>00223 <span class="comment">/* Points to the start of the pState buffer */</span>
241 <a name="l00224"></a>00224 pStateCurnt = S-><a class="code" href="structarm__lms__instance__q31.html#a206d47b49de6f357f933ebe61520753c">pState</a>;
242 <a name="l00225"></a>00225
243 <a name="l00226"></a>00226 <span class="comment">/* Loop unrolling for (numTaps - 1u) samples copy */</span>
244 <a name="l00227"></a>00227 tapCnt = (numTaps - 1u) >> 2u;
245 <a name="l00228"></a>00228
246 <a name="l00229"></a>00229 <span class="comment">/* copy data */</span>
247 <a name="l00230"></a>00230 <span class="keywordflow">while</span>(tapCnt > 0u)
248 <a name="l00231"></a>00231 {
249 <a name="l00232"></a>00232 *pStateCurnt++ = *pState++;
250 <a name="l00233"></a>00233 *pStateCurnt++ = *pState++;
251 <a name="l00234"></a>00234 *pStateCurnt++ = *pState++;
252 <a name="l00235"></a>00235 *pStateCurnt++ = *pState++;
253 <a name="l00236"></a>00236
254 <a name="l00237"></a>00237 <span class="comment">/* Decrement the loop counter */</span>
255 <a name="l00238"></a>00238 tapCnt--;
256 <a name="l00239"></a>00239 }
257 <a name="l00240"></a>00240
258 <a name="l00241"></a>00241 <span class="comment">/* Calculate remaining number of copies */</span>
259 <a name="l00242"></a>00242 tapCnt = (numTaps - 1u) % 0x4u;
260 <a name="l00243"></a>00243
261 <a name="l00244"></a>00244 <span class="comment">/* Copy the remaining q31_t data */</span>
262 <a name="l00245"></a>00245 <span class="keywordflow">while</span>(tapCnt > 0u)
263 <a name="l00246"></a>00246 {
264 <a name="l00247"></a>00247 *pStateCurnt++ = *pState++;
265 <a name="l00248"></a>00248
266 <a name="l00249"></a>00249 <span class="comment">/* Decrement the loop counter */</span>
267 <a name="l00250"></a>00250 tapCnt--;
268 <a name="l00251"></a>00251 }
269 <a name="l00252"></a>00252
270 <a name="l00253"></a>00253 <span class="preprocessor">#else</span>
271 <a name="l00254"></a>00254 <span class="preprocessor"></span>
272 <a name="l00255"></a>00255 <span class="comment">/* Run the below code for Cortex-M0 */</span>
273 <a name="l00256"></a>00256
274 <a name="l00257"></a>00257 <span class="keywordflow">while</span>(blkCnt > 0u)
275 <a name="l00258"></a>00258 {
276 <a name="l00259"></a>00259 <span class="comment">/* Copy the new input sample into the state buffer */</span>
277 <a name="l00260"></a>00260 *pStateCurnt++ = *pSrc++;
278 <a name="l00261"></a>00261
279 <a name="l00262"></a>00262 <span class="comment">/* Initialize pState pointer */</span>
280 <a name="l00263"></a>00263 px = pState;
281 <a name="l00264"></a>00264
282 <a name="l00265"></a>00265 <span class="comment">/* Initialize pCoeffs pointer */</span>
283 <a name="l00266"></a>00266 pb = pCoeffs;
284 <a name="l00267"></a>00267
285 <a name="l00268"></a>00268 <span class="comment">/* Set the accumulator to zero */</span>
286 <a name="l00269"></a>00269 acc = 0;
287 <a name="l00270"></a>00270
288 <a name="l00271"></a>00271 <span class="comment">/* Loop over numTaps number of values */</span>
289 <a name="l00272"></a>00272 tapCnt = numTaps;
290 <a name="l00273"></a>00273
291 <a name="l00274"></a>00274 <span class="keywordflow">while</span>(tapCnt > 0u)
292 <a name="l00275"></a>00275 {
293 <a name="l00276"></a>00276 <span class="comment">/* Perform the multiply-accumulate */</span>
294 <a name="l00277"></a>00277 acc += ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) (*px++)) * (*pb++);
295 <a name="l00278"></a>00278
296 <a name="l00279"></a>00279 <span class="comment">/* Decrement the loop counter */</span>
297 <a name="l00280"></a>00280 tapCnt--;
298 <a name="l00281"></a>00281 }
299 <a name="l00282"></a>00282
300 <a name="l00283"></a>00283 <span class="comment">/* Converting the result to 1.31 format */</span>
301 <a name="l00284"></a>00284 <span class="comment">/* Store the result from accumulator into the destination buffer. */</span>
302 <a name="l00285"></a>00285 acc = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (acc >> shift);
303 <a name="l00286"></a>00286
304 <a name="l00287"></a>00287 *pOut++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) acc;
305 <a name="l00288"></a>00288
306 <a name="l00289"></a>00289 <span class="comment">/* Compute and store error */</span>
307 <a name="l00290"></a>00290 e = *pRef++ - (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) acc;
308 <a name="l00291"></a>00291
309 <a name="l00292"></a>00292 *pErr++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) e;
310 <a name="l00293"></a>00293
311 <a name="l00294"></a>00294 <span class="comment">/* Weighting factor for the LMS version */</span>
312 <a name="l00295"></a>00295 alpha = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) e * mu) >> 31);
313 <a name="l00296"></a>00296
314 <a name="l00297"></a>00297 <span class="comment">/* Initialize pState pointer */</span>
315 <a name="l00298"></a>00298 <span class="comment">/* Advance state pointer by 1 for the next sample */</span>
316 <a name="l00299"></a>00299 px = pState++;
317 <a name="l00300"></a>00300
318 <a name="l00301"></a>00301 <span class="comment">/* Initialize pCoeffs pointer */</span>
319 <a name="l00302"></a>00302 pb = pCoeffs;
320 <a name="l00303"></a>00303
321 <a name="l00304"></a>00304 <span class="comment">/* Loop over numTaps number of values */</span>
322 <a name="l00305"></a>00305 tapCnt = numTaps;
323 <a name="l00306"></a>00306
324 <a name="l00307"></a>00307 <span class="keywordflow">while</span>(tapCnt > 0u)
325 <a name="l00308"></a>00308 {
326 <a name="l00309"></a>00309 <span class="comment">/* Perform the multiply-accumulate */</span>
327 <a name="l00310"></a>00310 coef = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) alpha * (*px++)) >> (32));
328 <a name="l00311"></a>00311 *pb += (coef << 1u);
329 <a name="l00312"></a>00312 pb++;
330 <a name="l00313"></a>00313
331 <a name="l00314"></a>00314 <span class="comment">/* Decrement the loop counter */</span>
332 <a name="l00315"></a>00315 tapCnt--;
333 <a name="l00316"></a>00316 }
334 <a name="l00317"></a>00317
335 <a name="l00318"></a>00318 <span class="comment">/* Decrement the loop counter */</span>
336 <a name="l00319"></a>00319 blkCnt--;
337 <a name="l00320"></a>00320 }
338 <a name="l00321"></a>00321
339 <a name="l00322"></a>00322 <span class="comment">/* Processing is complete. Now copy the last numTaps - 1 samples to the </span>
340 <a name="l00323"></a>00323 <span class="comment"> start of the state buffer. This prepares the state buffer for the </span>
341 <a name="l00324"></a>00324 <span class="comment"> next function call. */</span>
342 <a name="l00325"></a>00325
343 <a name="l00326"></a>00326 <span class="comment">/* Points to the start of the pState buffer */</span>
344 <a name="l00327"></a>00327 pStateCurnt = S-><a class="code" href="structarm__lms__instance__q31.html#a206d47b49de6f357f933ebe61520753c">pState</a>;
345 <a name="l00328"></a>00328
346 <a name="l00329"></a>00329 <span class="comment">/* Copy (numTaps - 1u) samples */</span>
347 <a name="l00330"></a>00330 tapCnt = (numTaps - 1u);
348 <a name="l00331"></a>00331
349 <a name="l00332"></a>00332 <span class="comment">/* Copy the data */</span>
350 <a name="l00333"></a>00333 <span class="keywordflow">while</span>(tapCnt > 0u)
351 <a name="l00334"></a>00334 {
352 <a name="l00335"></a>00335 *pStateCurnt++ = *pState++;
353 <a name="l00336"></a>00336
354 <a name="l00337"></a>00337 <span class="comment">/* Decrement the loop counter */</span>
355 <a name="l00338"></a>00338 tapCnt--;
356 <a name="l00339"></a>00339 }
357 <a name="l00340"></a>00340
358 <a name="l00341"></a>00341 <span class="preprocessor">#endif </span><span class="comment">/* #ifndef ARM_MATH_CM0 */</span>
359 <a name="l00342"></a>00342
360 <a name="l00343"></a>00343 }
361 <a name="l00344"></a>00344
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